1. Performance issues in summary

2. Query performance analyse

3. Cache monitor

4. ST03n

5. ST13

6. ST14

7. Statistics

8. ST02

9. BW Administration Cockpit

10. Optimizing performance of InfoProviders

11. ILM (Information Lifecycle Management)

12. BWA

13. Query analyzing example

14. General Hints

1. The common reasons for performance issues in summary

Causes for high DB-runtimes of queries

no aggregates/BWA

DB-statistics are missing

Indexes not updated

read mode of the query is not optimal

small sized PSAPTEMP

DB-parameters not optimal (memory and buffer)

HW: buffer, I/O, CPU, memory are not sufficient

Useage of OLAP Cache?

Causes for high OLAP runtimes

high amount of transmitted cells, because read mode is not optimal

user exits in query execution

usage of big hirarchies

Causes for high frontend runtimes

high amount of transmitted cells and formattings to the front-end

high latencies in refering WAN/LAN

insuffincient client hardware

2. Query performance analyse

I think this is a really important point (including the OLAP cache) and should be explained a little

bit deeper.

TA RSRT

To get exact runtimes for before/after analyze use this transaction with or without Cache/BWA

etc.

choose query execute and debug -> don´t use cache -> show statistic data

Button Properties

activate cache mode (also able to activate for the whole InfoProvider)

you should use the grouping, if you use multiprovider where data of only one Cube are changed

independent from the other ones. So you can avoid the invalidation of the cache.

Following grouping procedures are available:

1) no grouping

2) grouping depending on InfoProvider Types

3) grouping depending on InfoProvider Types InfoCubes Seperately

4) every Provider seperate

1) All results of an Infoprovider are stored together. If data of one of the Infoprovider are changed

the whole cache must be recreated. This setting should be used when all the Infoprovider, which

are used from the multiprovider, have the same load cycle.

2) All the results are stored grouped by the type of the InfoProvider. This option should be used

when a basic InfoCubes are combined with an realtime InfoCube.

3) Is the same as 2) with additionally the feature that every result of an Infocubes are stored

seperately. It should be used when you change/fill the cubes independent from each other.

4) Every results of a provider will be stored seperated (independent from the type). This option

should be used when not only, but also other provider types InfoCubes are updated seperately.

2.1 RSRT Query Properties

You can turn off parallel processing for a single query. In the case of queries with very fast

response times, the effort required for parallel processing can be greater than the potential time

gain. In this case, it may also make sense to turn off parallel processing.

Just play a little bit with RSRT and the different optionsto get the optimal settings for your

queries!

There are also some special read modes for a query. In the most cases the best choice is 'H' (Query

to be read when you navigate or expand hierarchies - more information)

2.1 RSRT Query properties with grouping

- Technical Info

- Performance Info

-> Useage of aggregates, Cache (+delta), compression, status of requests

2.2 RSRT Performance Info

3. Cache monitor

jump from RSRT into Cache monitor (TA: RSRCACHE)

Cache parameters

General infos about cache parameters, check them if they (runtime object and shared memory) are

all well sized. Therefore have also a look at the sap help.

There are 2 types of OLAP Cache, Cross-transaction cache and Local Cache (details on

help.sap.com).

!!!One thing you must know: the local cache is used in the following cases:

When the cross-transactional cache has been deactivated (see the parameter Cache Inactive).

When the cache was deactivated for the InfoProvider (for all future queries) or the query

If you determine during runtime that caching cannot take place

Main memory -> Objects inside in list or hirarchy display -> technical info (usage of selected

cache)

Check also buffer consumption under buffer monitor (Exp/ImpMem) and buffer overview (Exp./

Imp. SHM).

Check for which query it does make sense to save them in the OLAP cache, recommendations

from SAP:

How often the query is requested

We recommend that you save queries that are requested very frequently in the cache. Main

memory cache is very fast, but limited in size. By displacing cached data, you can cancel out main

memory limitations, but this also affects system performance. There are practically no limitations

on the memory space available in the database or in the file system for the persistent cache.

Accessing compressed data directly in the persistent cache also improves performance.

The complexity of the query

Caching improves performance for queries whose evaluation is more complex. We recommend

that you keep complex data processed by the OLAP processor in the cache. (Therefore the cache

mode Main Memory Without Swapping is less suitable for such queries.)

How often data is loaded

The cache does not provide an advantage if query-relevant data is frequently changed and

therefore has to be loaded frequently, since the cache has to be regenerated every time. If cached

data is kept in main memory, data from queries that are called frequently can be displaced, so that

calling the data takes more time

For detailed information which of the following modes should be used check sap help :

Cache is Inactive (0)

Main Memory Cache Without Swapping (1)

Main Memory Cache with Swapping (2)

Persistent Cache per Application Server (3)

Cross-Application Server Persistent Cache (4)

BLOB/Cluster Enhanced (5)

You can configurate this settings in RSRT (see screenshot 3.1)

3.1 RSRT performance info

3.2 RSRCACHE - Queries in Main Memory (BLOB/Cluster Enhanced is deactivated)

Use delta caching if possible. With this option you can avoid invalidation of the cache data when

the data basis are changed (data loads / process chains). So only the new data are read from the

DB.

Hint: Prefilling the OLAP cache via broadcasting (rsa1->administration->broadcasting;

documentation)

4. System load Monitor ST03n

ST03N (modi expert) -> click on BI system load to get data like:

Query runtimes (seperated BEx, BEx Web (ABAP / JAVA)

Process chain runtimes

DTP runtimes

Aggregate usage

5. ST13 Analyze & Service Toolset (depends on your ST-A/PI level)

there you can find some well known reports like RSECNOTE, but also new BI tools:

These tools use all RSDD* tables/views and displays them in a colorful and sorted way.

My favourites are BW-TOOLS, BW_QUERY_ACCESSES and BIIPTOOLS.

6. ST14

ST14 -> Business Warehouse -> plan analyze -> client 010 choose date , Basis Data (Top

BPSTOOLS BW-BPS Performance Toolset

BIIPTOOLS BI-IP Performance Toolset

BW_QUERY_ACCESSES BW: aggregate/InfoCube accesses of queries

BW_QUERY_USAGE BW: query usage statistics

BW-TOOLS BW Tools (PC Analyze, Request analyse, Aggregate toolset, IP

Analyse, DTP request analyse and IO Usage)

TABLE_ANALYSIS Table Analysis Tools

Objects) and Basis: Determine Top DB Objects and schedule it

you will get a great analyze for your whole BI system, including

top 30 PSA, E-fact, F-fact, Dimension, master data tables, change logs, Cubes ODS/DSO,

Aggregates and some special infos for BWA

for those who use oracle also Tables with more than 100 partitions

the upload performance for the last weeks

Compression rate

result of SAP_INFOCUBE_DESIGNS (D- and E-tables in relation to the F-tables)

...

6.1 ST14 Overview

If you have trouble with the growth of your system this is a great entry point to start your analyze

to find out where the space is gone ;)

So you know now which requests should be compressed and how to get rid of partitions (maybe

repartitioning; rsa1 -> administation -> repartitioning), but keep in mind that repartitioning creates

shadow tables in namespace /BIC/4E<InfoCubename> and /BIC/4F<InfoCubename>.

This tables are exists until the next repartitioning, so you can delete them after the repartitioning is

completed. Locate and delete empty F-partitions via report SAP_DROP_EMPTY_FPARTITION

(note 430486)

7. Statistics

TA: RSDDSTAT statistic recording (tracing) settings for for Infoprovider/queries etc.

Views RSDDSTAT_OLAP (OLAP + Frontend statistics) RSDDSTAT_DM (multiprovider,

aggregate-split, DB access time, rfc time)

Use TA SE11 to view there content.

Column AGGRAGATE to identify if it´s using aggregates or the BWA: aggregates are 1xxxxxx

and BWA-Indizes with <InfoCube>$X

How to delete statistics

TA RSDDSTAT (manual deletion)

setting up the tracelevel of queries and setting up deleletion of statistics

automatical deletion

Table RSADMIN Parameter TCT_KEEP_OLAP_DM_DATA_N_DAYS (DEFAULT 14 days)

date is relating field Starttime in table RSDDSTATINFO

8. ST02

check every instance for swaps -> double click on the red marked lines and then click on current

parameters and you will see which parameter you should increase.

Please read the sap help for each parameter it could be that there are dependencies!

(Memory and Buffer).

There are two possible reasons for swapping:

There is no space left in the buffer data area -> buffer is too small

There are no directory entries left -> Although there is enough space left in the buffer, no further

objects can be loaded because the number of directory entries is limited -> increase the needed

parameter for the directory entries!

Note : Before you change the settings, also have an eye on the pools via tool sappfpar! (on OS

as sidadm: sappfpar check pf=<path-to-profile> )

9. Using the BW Administration Cockpit

Setup via SPRO (BI -> Seetings for BI Content -> Business Intelligence ->BI Adminstration

Cockpit)

Prerequisites:

min. NW 7.0 Portal Stack 5 + BI Administration package 1.0

implement technical content (TA: RSTCC_INST_BIAC)

Report RSPOR_SETUP

Pros:

average and max. runtimes of queries

PC runtimes

trends for queries and bw-applications

suggestion for obsolet PSA data

9.1 compressed and not compressed requests

9.2 process chain status

10. Optimizing performance of InfoProviders in summary

Compress InfoCubes

Partitioning (and repartitioning) of InfoCubes

- DB level

- range partitioning (only for data base system which can handle partitions, e.g. oracle,

DB2, MSSQL)

- clustering

- application level

11. ILM (Information Lifecycle Management)

nearline (Vendors for nearline Storage are e.g. SAND Technology, EMC², FileTek, PBS ...)

archiving (Archiving via fileserver or stape drives)

deletion of data

Currently we don´t use any kind of ILM, but research is going on ;)

12. BWA Business Warehouse Accelerator (just a small summary):

RSDDTREX_MEMORY_ESTIMATE (see screenshot)-> to estimate the memory consumption of

the BWA for a specific InfoCube. That´s only the memory consumption and not the needed

storage on the hard disk!

RSDDV Display all your Indizes which are indexed by the BWA

RSRV Analyze BW objects

RSDDBIAMON2 BWA Monitor

TREX_ADMIN_TOOL (standalone tool)

Tables RSDDSTATTREX and RSDDSTATTREXSERV for analyzing the runtimes of BWA

Table RSDDTREXDIR (Administration of the TREX Aggregates) , check this blog for more

information

1) Report: RSDDTREX_INDEX_LOAD_UNLOAD to load or delete BWA Indizes from the

memory of the BWA servers. This can also be done over the RSRV ->Tests in Transaction RSRV

-> BI Accelerator -> BI Accelerator Performance Checks -> Load BIA index data into main

memory/Delete BIA index data from main memory.

2) Optimize Rollup process with BWA-Delta-Index via RSRV (Tests in Transaction RSRV -> All

Elementary Tests ->BI Accelerator ->BI Accelerator Performance Checks -> Propose Delta-Index

for Indixes )

Note that the Delta index growth with every load. The Delta index should not be bigger than 10%

of the main index. If this is the case -> merge both indexes via report

RSDDTREX_DELTAINDEX_MERGE

3) Use the BWA/BIA Index Maintenance Wizard for DFI Support or the option 'Always keep all

BIA index data in main store'. So they won´t be read from the disk, they stay always in memory!

You can also activate and monitore DFI support via the trexadmin standalone tool. Control your

memory consumption of BWA for this option!

12.1 result of report RSDDTREX_MEMORY_ESTIMATE

12.2 option index keep in memory via BWA/BIA Index Maintenance Wizard

12.3 BWA suggestion for delta indexes (RSRV, see 12. 2) )

13. Query analyzing example

find out which queries have a long runtime over ST03n:

13.1 ST03n - very high DB useage for this query

Check list

how often data in this infoprovider were changed?

RSRT -> Performance Info -> any aggregates, cache (+delta) mode, compression?

which Infoprovider were hit by the query? RSRT -> Technical Information (in our case

GRBCS_V11 - virtual cube and GRBCS_R11 - reporting cube)

DB statistics for this table/indexes up-to-date?

is it possible to index the Cube via BWA? (GRBCS_V11 can´t indexed because it is a virtual

Cube, GRBCS_R11 is already indexed, the GRBCS_V11 includes GRBCS_M11 - a realtime

infocube, which also can´t be indexed - and GRBCS_R11)

check where the most part of the runtime is spent (execute query in RSRT with options 'Display

Statistic Data' and 'Do not use Cache')

check table RSDDIME if Line Item Dimension or High Cardinality used (if you not sure when

you should use this features have a look below to the useful links)

In this case I would activate the OLAP Cache (which mode depends on the how often the basis

data are changed and if they are filled at the same time -> grouping for multiprovider, see point 2)

and talk to my colleagues which are responsible for modeling if we can change something on the

compression time frames. For more details you can also check table RSDDSTAT_DM.

The high runtime causes also from a bug in the db statistics (results in a bad execution plan) which

will be fixed in a merge fix (9657085 for PSU 1 and 10007936 for PSU2) for oracle 11g. (bug

9495669 see note 1477787)

13.2 You can see a high usage of the data manager (part of the analytic engine) = read access to the Infoproviders. In this case read time of the DB.

14. General Hints

1. Use high cardinality only where it makes sense! It could result in bad query performance. Use

table RSDDIME to get an overview over all properties of your dimensions.

2. Check in table RSRREPDIR (Field Cachemode) if for all queries cache and read mode 'H' are

activated (take also care of the Delta-Cache). If you have special cases for some queries, don´t

change your config. To change the read mode for all queries, call transaction RSRT -> type

'RALL' as "OK code", and press 'Enter'. In the dialog box, choose the new read mode and press

'Enter'. To change the read mode for a specific query, enter the name of the query and select 'Read

Mode'

3. Tablespace PSAPTEMP should have minimum size of 2 times of your biggest F-fact table (e.g.

we had some performance issues while executing some queries which are really took a lot of temp

space in cause of aggregating and sorting, so now our temp space is 4 times bigger than our

biggest F-table)

4. Table RSTODSPART shows the amount of records per request

5. BEx Information Broadcaster -> Fill OLAP-Cache via BEx Query Designer, BEx Analyzer, BEx

Web Analyzer, WAD, Portal and BEx Report Designer (Scheduling on daily, weekly or monthly

bases)

6. All tables of an InfoCube can be listed with TA LISTSCHEMA.

7. Report SAP_INFOCUBE_DESIGNS (Print a list of the cubes in the system and their layout)

8. Delete PSA-tables in your process chains

9. Delete Changelogs in your process chains

10. check if your aggregates are wise or not (TA: RSMON -> Aggregates)

11. Check SAP Note 1139396 and run reports SAP_DROP_TMPTABLES and

SAP_UPDATE_DBDIFF to clean obsolete temporary entries.

I hope I could give you some useful hints for your analyses. I appreciate any kind of feedback,

improvements and own experiences. Be careful with compression and partitioning, just use it if

you know what you are doing and what is happening with your data!!!

May be I could show an old stager some new tables/transactions